The Expires property specifies the length of time in minutes until a cached page on the browser expires.
The Expires property specifies a length of time in minutes before a response page cached on the browser expires.
<% Response.Expires = 0 %>
Causes the page to be refreshed (reloaded) every time it is accessed, rather than being stored in a cache.
<% Response.Expires = 15 %>If the user returns to this page before the 15 minutes are up, the cached version of the page will be displayed.